How popular is Dmitry?

Dmitry is an unusual first name for males. Dmitry is an uncommon surname too for both adults and children. (2000 U.S. Demographics)

Which version is better?

with its source form and related boy names. Prominent variation forms of Dmitry (outside Top 2000) listed in the Top 2000 are Demetrius(#676 in 2015), Dimitri(#905), Demetri(#1784), Dmitri(#1924) and Demitri. Usage of these forms of Dmitry reached its apex in the year 1992 (adoption of 0.09%) and is now significantly reduced (adoption 0.04%, 53% less). (2015 Birth Statistics)